The present invention is generally directed to coolant pumps employable in the cooling of electronic circuit components and modules. More particularly, the present invention is directed to an adaptable pump structure provided in modular form. Even more particularly, the present invention is directed to a stackable coolant pump in fluid connection with a liquid cooled cold plate which is in thermal contact with a circuit or module to be cooled.
The present invention is at least partially motivated by the fact that electronic circuit modules and other electrical components continue to dissipate increasingly larger amounts of thermal energy. For this reason, improved cooling technologies are highly desirable for carrying away this thermal energy. One method for cooling circuits employs a water cooling system in which a pump is used to convey water through a cold plate attached to an electronic module. In this approach heat is typically carried away to the ambient air through an air-to-water heat exchanger. This method is capable of handling relatively high heat fluxes occurring within the circuit modules.
Because of the above-mentioned higher circuit packaging densities and because of the desire to operate circuits, especially computer and communication circuits, at higher frequencies, power dissipation problems are now greater than ever and are expected to increase even more as both individual circuit elements and circuit chips are packed into smaller and smaller volumes. Because of this desire for packaging components in smaller volumes, the need for miniaturization also spills over into the design of any thermal energy dissipation system used to cool the electronics. Thus, because of the increased packaging density of the electronic components, miniaturized cooling system components are an equally strongly desired feature. Put another way, the goal of electronic circuit miniaturization would not be met by a system in which the electronic components were packaged as compactly as possible, but yet included unnecessarily large cooling system components which had not also been reduced in size by approximately the same scale factor.
One of the other factors that should be considered in pumps designed to provide cooling fluid for high thermal flux electronic circuit components is the ability to control the pump dimensions so as to be compatible with industry standard form factors, especially certain design height specifications. For example, the Electronic Industry Association (EIA) specifies a 1 U height of 1.75 inches for certain systems. Accordingly, a pump design should be scalable such that it is easy to maintain critical dimensioning so as to fit within these standard electronic packaging constraints. In particular, it is noted that the pump of the present invention is well able to fit within the 1 unit (1 U) EIA electronic package standard.
The present invention solves all of these problems above through the use of a liquid pump which provides high coolant flow rates and high coolant pressures. It provides this capability through the use of a modular and stackable pump structure which permits one to tailor the pump portion of the system to the thermal requirements of the electronic portion of the system without impacting important system dimensions. Moreover, the pump of the present invention is able to meet these goals and still meet the objective of providing miniaturized cooling system components, the key point here being that increased performance is achieved without increasing the overall size of the electronic package.
In accordance with one embodiment of the present invention a field configurable fluid pump comprises a plurality of modular pump units. Each of the modular units has a fluid inlet port and a fluid outlet port and a set of rotatable fluid moving vanes disposed within a substantially central volume. The pump units are sealed, one against the other, by arranging them in a stack. The bottom of an upper unit provides a sealing boundary for containment of the cooling fluid. The top of a lower unit provides the other boundary and a seal structure. (However, it is noted that this arrangement may be reversed with a seal element being disposed instead in the upper unit.) This seal is provided to prevent leakage between stacked units. A drive shaft extends through the modular pump units and is connected so as to rotate the vanes which act to move fluid from respective ones of the inlet ports to respective ones of the outlet ports. At least one removable fluid coupling conduit extends from one of the outlet ports to the inlet port in an adjacently disposed pump unit in the stack. It is this coupling which serves to provide a fluid connection between the modular pump units in the stack. The removable nature of this connection is significant in terms of the ability to provide a stacked structure with an easily adapted number of modular units. A sealing member (flat plate or nonfunctioning module unit) is disposed against the uppermost modular pump unit in the stack to provide a fluid seal for the central volume in the top unit.
In accordance with another embodiment of the invention there is provided a modular pump unit which is capable of being disposed in a stack with other units to form a larger pump structure with an increased flow rate and an increase in coolant fluid pressure. These modules include a housing having a substantially centrally disposed opening or cavity on its top side. This opening is typically and preferably cylindrical and it defines (when mated in a stack) a fluid flow volume for the modular pump unit. The housing also includes an inlet port and an outlet port both of which are in fluid communication with this internal cavity. A set of rotatable vanes are mounted on a drive axle which extends through a sealed opening in the bottom of the fluid flow cavity. These vanes are rotatable within the fluid flow volume so as to move fluid from the inlet port to said outlet port. There is also a seal disposed on the top side (or bottom side) of the housing so as to be capable of forming a seal with other modular pump units when they are disposed in a stacked configuration.
In accordance with yet another embodiment of the invention there is provided a cooled electronic system in which the stackable or field configurable fluid pump of the present invention is employed in conjunction with a cold plate in thermal contact with the components to be cooled. The cold plate includes channels for the passage of cooling fluid. Fluid conduits connect the pump, the cold plate and air-to-fluid heat exchangers in a closed loop with the heat exchangers preferably being disposed immediately downstream of the pump.
Accordingly, it is an object of the present invention to provide a stackable, field configurable pump for cooling fluids.
It is also an object of the present invention to provide a fluid pump which is constructed from a plurality of common parts which thus reduces the cost of production.
It is a still further object of the present invention to provide a pump design structure wherein fluid pressure can be increased and especially wherein this pressure increase is produced in already existing pump units.
It is yet another object of the present invention to provide fluid pump structures which meet defined standard size requirements.
It is a further object of the present invention to provide a pump structure in which the designed for fluid flow rate can be adjusted by increasing the width of the impeller.
It is also an object of the present invention to provide a stackable pump structure in which fluid communications from one modular pump unit to the next pump unit is provided by snap-in-piping, such as through the use of piping which is sealed to the pump body with an O-ring or O-ring type seal.
It is a still further object of the present invention to provide a pump design which is scalable.
It is yet another object of the present invention to provide a modularly constructable pump whose dimensions are easily controllable so as to permit it to fit within spaces having predefined, standard height requirements.
It is also an object of the present invention to provide smooth transitions internal to the pump resulting in low pressure losses.
It is a further object of the present invention to provide a pump which can be driven by a motor of choice which also meets standard dimensional constraints.
It is yet another object of the present invention to provide a pump which is easily mountable in its designed-for environment.
It is also an object of the present invention to provide a pump which is simple to manufacture and which may be made from a wide variety of materials with at least some of these materials being selectable because of their machinability properties.
Lastly, but not limited hereto, it is an object of the present invention to increase the speed and packing density of electronic circuits by providing enhanced cooling systems which are dimensioned to be compatible with the circuit miniaturization which accompanies the increased packing densities.
The recitation herein of a list of desirable objects which are met by various embodiments of the present invention is not meant to imply or suggest that any or all of these objects are present as essential features, either individually or collectively, in the most general embodiment of the present invention or in any of its more specific embodiments.